Preventing Fungal and Bacterial Growth Using Ethanol and Soap Solutions
by: Avery Moe and Mia Gambucci

Audacity overview of our project:




PREVENTING BACTERIAL AND FUNGAL GROWTH USING ETHANOL AND SOAP SOLUTIONS. Avery Moe and Mia Gambucci. The purpose of this experiment was to determine the antibacterial and antifungal efficiency of different concentrations of ethanol, hand soap and PURELL sanitizer. Cultures of fungus and bacteria were spread on multiple agar plates, and antibacterial discs saturated with different dilutions of ethyl alcohol and hand soap were added to the plates. The diameter of the ring of inhibited growth (the zone of inhibition) was measured after the plates were allowed to grow. It was found that hand soap acts as an effective antibacterial agent when it is least diluted. The ethanol solutions did not inhibit growth of either the bacteria or the fungus. Because the results with ethanol were unexpected, a third trial was run using only different dilutions of liquid hand soap. It was determined from these results that the efficiency of hand soap as a cleanser did not depend on its concentration. It was also concluded that the zone of inhibition test is not a proper way to test the efficiency of ethanol as a sanitizer.Keywords: Inhibition zone, antibiotic disc, nutrient agar, potato agar, agar plates, Aspergillus niger, fungus, Escherichia coli, bacteria


Figure 1: Lab apparatusall_plates-bacteria.jpg

Figure 2: Summary of Results
bacteria_graph.JPG

Graph 1: bacteria with ethanol solutions, PURELL and hand soap


fungus_graph.JPGGraph 2: Fungus with ethanol solutions, Purell, and hand soap
soap_graph.JPG
Graph 3: Bacteria with hand soap solutions



Citations:


Journal 1:
Fendler, E, & Groziak, P. (2002). Efficacy of alcohol-based hand sanitizers against fungi and
viruses. Infection Control and Hospital Epidemiology, 23(2), 61-62.


Journal 2: Barry, A, Coyle, M, Thornsberry, C, Gerlach, H, & Hawkinson, R. (1979). Methods of measuring zones of inhibition with the Bauer-Kirby disk susceptibility test. Journal of Clinical Microbiology, 10(6), 885-889.